Preparation of Multi-walled Carbon Nanotubes-Au Nanoparticles Modified GCE and Its Application to Determination of Kojic Acid

Nano composite of multiwalled carbon nanotubes (MWCNT′s) loaded with nano particles of gold (Au/MWCNT′s) was prepard, and a dispersion of the composite in Nafion-ethanol solution was added dropwise onto the surface of glassy carbon electrode to prepare the modified electrode designated abbreviately as Au/MWCNT′s/GCE. Specific features of the functionalized MWCNT′s was tested by IRS, and characterization of the composite Au/MWCNT′s was performed by TEM and XRD. It was found that in an acetate buffer medium of pH 6.0, kojic acid exhibited significant electrocatalytic oxidation at this modified electrode. Under the optimized conditions, linear relationship between values of peak current and concentration of kojic acid was kept in the range of 1×10-3-5.5×10-3mol·L-1 with detection limit (3S/N) of 2.0×10-5mol·L-1.